Herbal products have gained widespread popularity in the United States, with up to one-quarter of adults reporting use of an herb to treat a medical illness within the past year. Although herbs are commonly perceived as safe and "natural," numerous serious side effects have been reported, including myocardial infarction, stroke, liver failure, end-stage renal disease, and death. Unfortunately, surveillance systems to detect side effects of herbal products are extremely limited. Most serious reactions to herbs (including Chinese herb nephropathy and kava-kava related hepatitis) have been identified through case reporting, an inefficient system of monitoring that captures only a small percentage of all adverse events and only after large numbers of patients have been exposed. Current monitoring systems can be described as "passive," since action is only taken after enough case reports accumulate to raise concern of a possible dangerous adverse reaction. This career development program will provide the applicant with mentored training and research experience to examine the ability of "active" systems to detect adverse reactions to herbs at an early phase, before severe clinical outcomes occur. After completing an extensive curriculum in pharmacognosy, pharmacoepidemiology, and the analysis of complex cohort data, Dr. Bent will conduct four research projects that address two specific aims. The first specific aim is to determine if secondary data analysis is able to detect associations between specific herbs and laboratory and clinical outcomes that may represent adverse reactions. This will be addressed by three studies that examine 1) associations in a completed randomized controlled trial, 2) associations in an existing patient database, and 3) a comparison of the sensitivity and specificity of the two methods. The second specific aim is to determine the ability of a prospective cohort study to detect associations between specific herbs and laboratory/clinical outcomes that may represent adverse events. A cohort of patients at high risk for herb-drug interactions (patients on long-term anticoagulation) will be established to determine if herbal product use is associated with poor control of anticoagulation or related adverse clinical outcomes. Ultimately, this research strives to identify improved methods for the early detection of adverse events, providing patients with a safer environment to achieve the potential benefits of herbal products.